This invention relates to electronic devices, and more particularly to portable media devices that have video capabilities.
Videos provided on the Internet are becoming a popular form of media. Conventionally, Internet-provided videos are displayed on personal computer (PC) or laptop monitors, where the screen sizes are relatively small. However, with improvements in networking, Internet content may be displayed on other devices with larger screens, such as on television screens. Internet-provided videos differ from videos typically displayed on a television, since Internet-provided videos generally have low resolution. Therefore, when Internet content is shown on a large-screen television, there may be very little detail in the picture, creating an unpleasant viewing experience.
In addition, many videos on the Internet are user-generated, and are thus created by amateurs who are unfamiliar with or unable to use professional techniques in video-generation. For example, user-generated videos may be filmed on hand-held video cameras. Thus, due to the shaking camera, the frame-by-frame video may change even for unchanging backgrounds. For a given data rate, this causes a disproportionate amount of compressed video data to be used on backgrounds and other still images. For this and other reasons, user-generated content often suffers not only from low resolution, but also from artifacts. Artifacts are referred to herein as visually displeasing portions in a display that are caused by video compression. Common artifacts include blocking artifacts and mosquito noise. Blocking artifacts refer to the blocky appearance of a low resolution video that is typically seen on areas of less detail in the image. Mosquito noise is a ringing effect, caused by truncating high-frequency luminance and/or chrominance coefficients, typically seen around sharp edges in the video. When videos with low resolution and compression artifacts are blown up to a large size, the picture quality may become unacceptably poor.
Furthermore, processing techniques performed by large-screen display devices when preparing a video signal for display on the device may worsen the presentation of low-resolution video. One such processing technique performed by display devices is deinterlacing, a process that changes the way that pixels are drawn on a screen. Videos are displayed by a display device by drawing successive images at fast enough rate (e.g., 50 frames per second). Typically, a display presents these images pixel by pixel using either a progressive or interlaced scan. A progressive scan draws out each pixel in an image from the top of the screen to the bottom. Thus, after each scan, a progressive display displays an entire frame. An interlaced scan, on the other hand, draws out the odd pixel lines in an image. Then, at the next time instant, the even pixel lines are drawn out. An interlaced scan, therefore, creates a video by alternating between displaying the odd lines and displaying the even lines of successive images. These half-resolution images are called fields.
Currently, many display devices (e.g., some digital televisions, liquid crystal displays (LCDs), etc.) are progressive displays. However, video transmission standards, such as television broadcast standards, commonly use interlacing. Therefore, these display devices often include deinterlacing circuitry for converting interlaced videos to progressive videos. There are several different deinterlacing techniques employed by digital display devices. These techniques attempt to display an interlaced video with the highest possible visual quality. Thus, to effectively display television broadcasts and other interlaced videos, the deinterlacing circuitry in televisions and other display devices are becoming increasingly complex and sophisticated.
In general, because of these deinterlacing and other new, sophisticated techniques for effectively processing higher-resolution video signals, viewers have come to expect vivid and high-quality images on their television sets. In particular, these techniques are being incorporated into regularly available television sets for displaying large images with higher brightness, contrast, and resolution. However, these deinterlacing and/or other complex processing techniques may not be effective when performed on low-resolution and/or low frame rate, and possibly poorly compressed, videos. Therefore, there is currently no effective way to present both high-resolution video content, such as television broadcasts, and low-resolution video content, such as Internet content, on a large-screen device. Thus, it would be desirable to improve the appearance of low-resolution video on large-screen displays.
Other than videos from the Internet, videos may be provided by portable media players or other portable media devices that are either captured by the device or obtained elsewhere. These portable devices are capable of storing and providing a large amount of video content. In fact, many of these portable media players may store 80 Gigabytes or more of video content. With that much memory, a portable media player can store and playback many hours of video content. Thus, users can easily carry around devices with large amounts of video content.
Also, as technology improves, these portable media devices are becoming increasingly complex, and may therefore have an increasing number of functions. For example, there are cellular telephones with video capture, storage, and playback capabilities. Thus, the media stored by portable media devices may include video captured by the device itself. The quality of a captured video, in terms of resolution and frame rate, may be acceptable when the video is played back on the small display of the portable media device. Yet, because of the small size of the portable media device display, it may be desirable to display the captured video content on a large screen display, such as on a television. However, because of a viewer's high expectation of content quality on televisions and other large-screen devices, when a video captured by a portable media device is displayed on the large screen, a viewer may find the video content unacceptably poor.
Thus, it would also be desirable to provide a method or system for effectively displaying videos captured from a portable media device, or other videos captured with low resolution and/or low frame rate, on a large-screen device.